Couldn't agree more with need to be super organised, also I had a conversation with lo ( not in the morning I add !) about what it was important to do in the morning and what wasn't, we had very different ideas ha.
We then wrote a checklist that we ticked off ( photocopy and use each day) my lo loved doing this.
Finally we typed a letter which went like this :
Dear Mr B ( headteacher)
I am sorry I am late this morning
This is because ..............(i.e, i didn't listen to my mummy telling me to get dressed)
yours truly
then a space for them to sign their name.
I would refer to checklist and letter through the morning , "oh no i don't think we are going to get everything done on the list , we will have to sign the letter , quick lets see if we can do it"
This made my , and my lo's, morning much less stressful and even meant we often had time at the end for a bit of play , reading , etc.
I know not everything works the same for each child but some friends have used it and its worked for them too .
I think if children get the idea that you are trying to do it together and not nagging them , shouting etc. they are much more likely to do it ( same for me as well, I'm the worlds biggest refuser if I feel I am being nagged, ha )